IF not EXISTS( SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Bargeh' AND  COLUMN_NAME = 'Con_ID')
begin
	alter table Bargeh add Con_ID	int references [Contract](ID) null
end
;
IF not EXISTS( SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'DaryaftPardakht' AND  COLUMN_NAME = 'Con_ID')
begin
	alter table DaryaftPardakht add Con_ID	int references [Contract](ID) null
end